The present invention relates to electrical devices having magnetically coupled drives, and particularly to electrical shavers of the type described in my U.S. patent application Ser. No. 09/312,765, filed May 17, 1999, which application issued as U.S. Pat. No. 6,226,870, which application claims the benefit of Provisional Patent Application Ser. No. 60/164,771 filed Nov. 12, 1999, Provisional Patent Application Ser. No. 60/154,034 filed Sep. 16, 1999, Provisional Patent Application Ser. No. 60/145,803, filed Jul. 27, 1999, and Provisional Patent Application Ser. No. 60/142,943, filed Jul. 12, 1999. The invention also relates to adapters for use with existing electrical devices, particularly electrical shavers, to provide a magnetic coupling enabling the motor housing of such devices to be sealed against the entry of water or other foreign substances.
My above-identified patent application describes an electrical shaver comprising a housing including a rotary electrical motor and at least one drive magnet within the housing and mechanically coupled to the electrical motor to be rotated thereby; a cutter holder externally of the motor housing and including a cutter head (preferably three); and a driven magnet externally of the housing for each drive magnet within the motor housing. The driven magnet is magnetically coupled to the respective drive magnet within the housing so as to be rotated thereby, and is mechanically coupled to the cutter heads so as to rotate them when the driven magnet is rotated by the drive magnet. As described in that patent application, the electrical motor within the housing is completely sealed from exposure to water, and therefore such an electrical shaver may be used not only for conventional dry shaving, but also for wet shaving (with soap and water) in order to produce a close shave and a clean after-feeling as when wet shaving with a blade. The contents of that patent application are incorporated herein by reference.
In the embodiments of the invention described in that patent application, the driven magnet is included in the cutter holder unit. While such a construction is capable of producing a more compact arrangement, it requires redesign of the existing cutter holder units, and therefore can not easily accommodate the many existing designs of cutter holder units.